hollyfield is at the scene. amy, what are investigators saying about a cause? >> reporter: they say it could have been a malicious act. they questioned someone who heard from someone that they saw something. firefighters say it's not a strong lead, but they are following up on it. it is still early. whatever caused this fire, it did millions of dollars of damage. the fire spread quickly and was aggressive, traveling to three biddle before firefighters could get here. people sleeping woke up and felt a mixture of fear and shock. >> oh, my gosh! wow. you know what, it was so big it was going -- i could see it billowing over to my window, you know. and it was just, wow, humongous. >> reporter: the fire caused significant damage to three buildings. water from the firefighters' hoses flooded the first floor of two other buildings. firefighters determined that the fire started in between two buildings on mckinnon street on 3rd street in the bayview district just before 1:00 this morning. >> there were 20 citizens displaced by this fire. american red cross has been working with the displaced reside